Method and system for offline indexing of content and classifying stored data

ABSTRACT

A method and system for creating an index of content without interfering with the source of the content includes an offline content indexing system that creates an index of content from an offline copy of data. The system may associate additional properties or tags with data that are not part of traditional indexing of content, such as the time the content was last available or user attributes associated with the content. Users can search the created index to locate content that is no longer available or based on the associate attributes.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to U.S. Provisional ApplicationNo. 60/852,584 entitled “METHOD AND SYSTEM FOR COLLABORATIVE SEARCHING,”and filed on Oct. 17, 2006, which is hereby incorporated by reference.

BACKGROUND

Computer systems contain large amounts of data. This data includespersonal data, such as financial data, customer/client/patient contactdata, audio/visual data, and much more. Corporate computer systems oftencontain word processing documents, engineering diagrams, spreadsheets,business strategy presentations, and so on. With the proliferation ofcomputer systems and the ease of creating content, the amount of contentin an organization has expanded rapidly. Even small offices often havemore information stored than any single employee can know about orlocate.

Many organizations have installed content management software thatactively searches for files within the organization and creates an indexof the information available in each file that can be used to search forand retrieve documents based on a topic. Such content managementsoftware generally maintains on index of keywords found within thecontent, such as words in a document.

Creating a content index generally requires access to all of thecomputer systems within an organization and can put an unexpected loadon already burdened systems. Some organizations defer content indexinguntil off hours, such as early in the morning to reduce the impact tothe availability of systems. However, other operations may compete forsystem resources during off hours. For example, system backups are alsogenerally scheduled for off hours. Systems may be placed in anunavailable state during times when backups are being performed, calledthe backup window, to prevent data from changing. For organizations withlarge amounts of data, any interruption, such as that from contentindexing, jeopardizes the ability to complete the backup during thebackup window.

Furthermore, traditional content indexing only identifies informationthat is currently available within the organization, and may beinsufficient to find all of the data required by an organization. Forexample, an organization may be asked to produce files that existedduring a past time period in response to a legal discovery request.Emails from five years ago or files that have been deleted or are nolonger available except in offsite backup tapes may be required toanswer such a request. An organization may be obligated to go throughthe time consuming task of retrieving all of this content and conductinga manual search for content related to the request.

There is a need for a system that overcomes the above problems, as wellas providing additional benefits.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram that illustrates components of a system, inone embodiment of the invention.

FIG. 2 is a block diagram that illustrates flow of data through thesystem, in one embodiment.

FIG. 3 is a flow diagram that illustrates processing of a contentindexing component of the system, in one embodiment.

FIG. 4 is a flow diagram that illustrates processing of an indexsearching component of the system, in one embodiment.

FIG. 5 illustrates a data structure containing entries of a contentindex, in one embodiment.

In the drawings, the same reference numbers and acronyms identifyelements or acts with the same or similar functionality for ease ofunderstanding and convenience. To easily identify the discussion of anyparticular element or act, the most significant digit or digits in areference number refer to the Figure number in which that element isfirst introduced (e.g., element 1104 is first introduced and discussedwith respect to FIG. 11).

The headings provided herein are for convenience only and do notnecessarily affect the scope or meaning of the claimed invention.

DETAILED DESCRIPTION

Overview

A method and system for creating an index of content without interferingwith the source of the content including an offline content indexingsystem that creates an index of content from an offline copy of data isprovided. In general, organizations may have a primary or productioncopy of source data and one or more offline or secondary copies of data.Secondary copies can be created using various storage operations such assnapshots, backups, replication, migration, and other operations. Theoffline content indexing system can create an index of an organization'scontent by examining secondary copies of the organization's data (e.g.,backup files generated from routine backups performed by theorganization). The offline content indexing system can index contentfrom current secondary copies of the system as well as older offlinecopies that contain data that may no longer be available on theorganization's network. For example, the organization may have secondarycopies dating back several years that contain older data that is nolonger readily available, but may still be relevant to the organization.The offline content indexing system may associate additional propertieswith data that are not part of traditional indexing of content, calledmetadata, such as the time the content was last available or userattributes associated with the content. For example, user attributessuch as a project name with which a data file is associated may bestored.

Members of the organization can search the created index to locatecontent that is no longer readily available or based on the associatedattributes. For example, a user can search for content related to aproject that was cancelled a year ago. Thus, users can find additionalorganization data that is not available in traditional content indexingsystems. Moreover, by using secondary copies, content indexing does notimpact the availability of the system that is the original source of thecontent.

In some embodiments, members of the organization can search for contentwithin the organization through a single, unified user interface. Forexample, members may search for content that originated on a variety ofcomputer systems within the organization. Thus, users can accessinformation from many systems within the organization and can search forcontent independent of the content's original source. Members may alsosearch through multiple copies of the content, such as the originalcopy, a first secondary backup copy, and other secondary or auxiliarycopies of the content.

Various attributes, characteristics, and identifiers (sometimes referredto as tags or data classifications) can be associated with content. Thesystem may define certain built-in tags, such as a document title,author, last modified date, and so on. Users of the system may alsodefine custom tags, or the system may automatically define custom tags.For example, an administrator may add tags related to groups within anenterprise, such as a tag identifying the department (e.g., finance,engineering, or legal) that created a particular content item.Individual users may also add tags relevant to that user. For example, auser might add a descriptive field, such as a programmer adding acheck-in description to identify a change made to a version of a sourcecode document. For content that is inherently unstructured or appearsrandom outside of its intended purpose, tags are an especially effectiveway of ensuring that a user can later find the content. For example,United States Geological Survey (USGS) data is composed of many numbersin a file that have little significance outside of the context of a mapor other associated viewer for the data. Tags allow descriptiveattributes or other meaningful information to be associated with thedata, for example, so that a searching user can know at a glance thatparticular USGS data refers to a topological map of a nearby lake. Tagsmay be associated with offline and online data through a metabase orother suitable data structure that stores metadata and references to thecontent to which the metadata applies. FIG. 5, discussed below,describes one exemplary data structure used to store user tagsassociated with content.

The invention will now be described with respect to various embodiments.The following description provides specific details for a thoroughunderstanding of, and enabling description for, these embodiments of theinvention. However, one skilled in the art will understand that theinvention may be practiced without these details. In other instances,well-known structures and functions have not been shown or described indetail to avoid unnecessarily obscuring the description of theembodiments of the invention.

The terminology used in the description presented below is intended tobe interpreted in its broadest reasonable manner, even though it isbeing used in conjunction with a detailed description of certainspecific embodiments of the invention. Certain terms may even beemphasized below; however, any terminology intended to be interpreted inany restricted manner will be overtly and specifically defined as suchin this Detailed Description section.

Creation of an Offline Copy

As discussed above, the offline content indexing system may create asecondary copy, such as an offline copy, as part of an existing backupschedule performed by an organization. For example, an organization mayperform weekly backups that contain a complete copy of theorganization's data. It is generally not necessary for the offlinecontent indexing system to consume any further resources of the computersystems within the organization that contain source content, since allof the needed data is typically available in the backup data files. Theoffline content indexing system may restore the backed up data to anintermediate computer system that is not critical to the operation ofthe organization, or may operate on the backup data files directly toidentify and index content. The offline content indexing system may alsocreate the offline copy using copies of data other than a traditionalbackup, such as a snapshot, primary copy, secondary copy, auxiliarycopy, and so on.

In some embodiments, the offline content indexing system uses a changejournal to create an offline copy of content. Modern operating systemsoften contain built in change journaling functionality that stores ajournal entry whenever data is changed within a computer system. Thechange journal generally contains a step-by-step, sequential, or orderedlog of what data changed and how the data changed that can be processedat a later time to recreate the current state of the data. The changejournal may be used in conjunction with a full data backup or other dataprotection mechanisms. The full backup can be used to establish thestate of the data at a prior point-in-time, and then the change journalentries can be used to update the state with subsequent changes.

In some embodiments, the offline content indexing system or other systemuses a data snapshot to create an offline copy of content. Neweroperating systems and several data storage companies offer snapshotsoftware capable of taking a snapshot of the content currently on acomputer system with minimal impact to the availability of the system.For example, the snapshot may simply note the current entry in a changejournal, and keep track of subsequent change journal entries forupdating the snapshot. These snapshots can be transferred from the hostsystem and read on another, less critical system or can be used toreplicate the data to a different. The offline content indexing systemcan then access this intermediate system to identify content and performcontent indexing. Other technologies that will be recognized by thoseskilled in the art, such as disk imaging, mirroring, incrementalbackups, and so on, may be used in a manner similar to create an offlinecopy of data for content indexing.

In some embodiments, the offline content indexing system selects anoffline copy of data for indexing among several available offlinecopies. For example, an organization may have several copies of dataavailable on different types of media. The same data may be available ona tape, on a backup server, through network attached storage, or on fastmounted disk media. The offline content indexing system may take intoconsideration factors such as the access time of a particular media andthe scheduled load on a particular offline copy when selecting a copy touse for indexing. For example, an offline copy stored on a hard drivemay be preferred over a copy stored on tape due to the faster accesstime of the hard drive copy and the ability to randomly seek among thedata rather than accessing the data sequentially. Alternatively oradditionally, a backup server storing or responsible for otherwisedesirable data to index scheduled to perform an intensive operation suchas encrypting content may be skipped in favor of using a differentserver responsible for an offline copy that is not expected to be neededby other systems during the time expected to index the content.Similarly, the offline content indexing system may prefer an unencryptedoffline copy over an encrypted one due to the extra effort required todecrypt the content to index it.

Indexing of Content

In some embodiments, the offline content indexing system may wait toindex content until a request related to the content is received.Searches for offline content may not be as time sensitive as searchesfor currently available content such that the effort of indexing thecontent can be postponed until the content is required. For example, ina legal discovery request there may be several days or even weeksavailable to find content responsive to the request, such that indexingbefore a request is received would unnecessarily burden anorganization's systems.

In some embodiments, the offline content indexing system may postponecontent indexing until other storage operations have been performed. Forexample, one storage operation, called single instancing, may reduce oreliminate redundant files contained in backup data caused by manysystems containing the same operating system or application files. Bypostponing content indexing until after single instancing has occurred,the offline content indexing system does not have to search as much dataand may complete the indexing process sooner and with less burden to theorganization's systems. A storage policy or other system parametersetting or preference may define how and when content indexing is done,and what other operations are performed before and after contentindexing (e.g., indexing content after single instancing). A storagepolicy is a data structure that stores information about the parametersof a storage operation. For example, the storage policy may define thatonly some content is to be indexed, or that content indexing shouldoccur late at night when system resources are more readily available.

In some embodiments, the offline content indexing system may update acontent index according to an indexing policy. An indexing policy is adata structure that stores information about the parameters of anindexing operation. For example, an organization may create a fullbackup once a week, and may create an indexing policy that specifiesthat the index should be updated following each weekly full backup.Indexing the full backup creates a reference copy that the organizationcan store according to legal requirements (e.g., ten years) to respondto any compliance requests. The indexing policy may also specify thatincremental updates are performed on the index based on incrementalbackups or other incremental data protection operations such as updatesfrom a change journal or snapshot application. For example, incrementalbackups may be created that only specify the data that has changed sincethe last full backup, and content changes identified within theincremental backup may be used by the offline content indexing system toupdate the index to reflect the new state of the content. If the backupdata indicates that content has been deleted, the indexed content may beretained, but may be flagged or otherwise identified as having beendeleted.

Content Tags

In some embodiments, the offline content indexing system tags orotherwise identifies indexed content with additional information thatmay help identify the information, for example, in a search for content.For example, indexed content may be tagged with the location of theoffline copy in which the information was found, such as a particularbackup tape or other offline media. The system may also tag onlinecontent, such as tagging a new file with the name of its author. If thecontent is later deleted, the indexed content may be tagged with thedate the content was deleted, the user or process that deleted thecontent, or the date the content was last available. Deleted content maylater be restored, and the indexed content may be identified by aversion number to indicate versions of the content that have beenavailable on computing systems throughout the content's history. Otherinformation about the content's availability may also be stored, such aswhether the content is stored onsite or is archived offsite, and anestimate of the time required to retrieve the content. For example, ifthe content is stored offsite with an external archival company, thecompany may require one week's notice to retrieve the content, whereasif the content is stored on a tape within the organization, the contentmay be available within an hour. Other factors may also be used toprovide a more accurate estimate, such as the size of the content, theoffset of the content if it is on tape, and so on. During a search, thesearch results may indicate whether the time required to retrievecertain content would exceed a retrieval threshold. The system may alsoprohibit transferring content beyond a given retrieval time to ensurecompliance with a policy of the organization.

In some embodiments, the offline content indexing system tags contentwith classifications. For example, the offline content indexing systemmay classify content based on the type of application typically used toprocess the content, such as a word processor for documents or an emailclient for email. Alternatively or additionally, content may beclassified based on the department within the organization thatgenerated the content, such as marketing or engineering, or based on aproject that the content is associated with such as a particular casewithin a law firm. Content may also be classified based on access rulesassociated with the content. For example, some files may be classifiedas confidential or as only being accessible to a certain group of peoplewithin the organization. The system may identify keywords within thecontent and classify the content automatically based on identifiedkeywords or other aspects of the content.

Searching

In some embodiments, the offline content indexing system searches forcontent based on temporal information related to the content. Forexample, a user may search for content available during a specified timeperiod, such as email received during a particular month. A user mayalso search specifically for content that is no longer available, suchas searching for files deleted from the user's primary computer system.The user may perform a search based on the attributes described above,such as a search based on the time an item was deleted, or based on aproject that the item was associated with. A user may also search basedon keywords associated with user attributes, such as searching for filesthat only an executive of the organization would have access to,searching for files accessed by a particular user, or searching forfiles tagged as confidential.

In some embodiments, the offline content indexing system provides searchresults that predict the availability of content. For example, contentstored offsite may need to be located, shipped, and then loaded backinto the organization's systems before it is accessible. The offlinecontent indexing system may provide a time estimate of how soon thecontent could be available for searching as well as providing limitedinformation about the content immediately based on data stored in theindex. For example, the content indexing system may maintain a databaseof hardware and libraries of media available with the organization, aswell as the current location of each of these items such that anestimate can be generated for retrieving the hardware or libraries ofmedia. For example, certain tape libraries may be stored offsite after aspecified period of time, and content stored within the tape library maytake longer to retrieve than content in a tape library stored onsite inthe organization. Similarly, the offline content index system mayestimate that data stored on tape will take slightly longer to retrievethan data that is available through magnetic storage over the network.

Figures

Unless described otherwise below, aspects of the invention may bepracticed with conventional systems. Thus, the construction andoperation of the various blocks shown in FIG. 1 may be of conventionaldesign, and need not be described in further detail herein to make anduse the invention, because such blocks will be understood by thoseskilled in the relevant art. One skilled in the relevant art can readilymake any modifications necessary to the blocks in FIG. 1 (or otherembodiments or Figures) based on the detailed description providedherein.

FIG. 1 is a block diagram that illustrates components of the system, inone embodiment. The offline content indexing system 100 contains anoffline copy component 110, a content indexing component 120, an indexsearching component 130, an index policy component 140, a dataclassification component 150, a single instancing component 160, anencryption component 170, and an archive retrieval component 180. Theoffline copy component 110 creates and identifies offline or othersecondary copies of data, such as backup data, snapshots, and changejournal entries. The content indexing component 120 creates and updatesa content index based on offline copies of data. The index searchingcomponent 130 searches the index based on user requests to identifytarget content. The index policy component 140 specifies a schedule forupdating the content index incrementally or refreshing the contentindex, such as from a full weekly backup. The data classificationcomponent 150 adds data classifications to the content index based onvarious classifications of the data, such as the department that createdthe data, and access information associated with the data. The singleinstancing component 160 eliminates redundant instances of informationfrom offline copies of data to reduce the work involved in creating anindex of the offline copy of the data. The encryption component 170encrypts and decrypts data as required to permit access to the data forcontent indexing. The archive retrieval component 180 retrieves archivedcontent from offsite storage, tape libraries, and other archivallocations based on requests to access the content and may also provideestimates of the time required to access a particular content item.

FIG. 1 and the following discussion provide a brief, general descriptionof a suitable computing environment in which the invention can beimplemented. Although not required, aspects of the invention aredescribed in the general context of computer-executable instructions,such as routines executed by a general-purpose computer, e.g., a servercomputer, wireless device or personal computer. Those skilled in therelevant art will appreciate that the invention can be practiced withother communications, data processing, or computer systemconfigurations, including: Internet appliances, hand-held devices(including personal digital assistants (PDAs)), wearable computers, allmanner of cellular or mobile phones, multi-processor systems,microprocessor-based or programmable consumer electronics, set-topboxes, network PCs, mini-computers, mainframe computers, and the like.Indeed, the terms “computer,” “host,” and “host computer” are generallyused interchangeably herein, and refer to any of the above devices andsystems, as well as any data processor.

Aspects of the invention can be embodied in a special purpose computeror data processor that is specifically programmed, configured, orconstructed to perform one or more of the computer-executableinstructions explained in detail herein. Aspects of the invention canalso be practiced in distributed computing environments where tasks ormodules are performed by remote processing devices, which are linkedthrough a communications network, such as a Local Area Network (LAN),Wide Area Network (WAN), Storage Area Network (SAN), Fibre Channel, orthe Internet. In a distributed computing environment, program modulesmay be located in both local and remote memory storage devices.

Aspects of the invention may be stored or distributed oncomputer-readable media, including magnetically or optically readablecomputer discs, hard-wired or preprogrammed chips (e.g., EEPROMsemiconductor chips), nanotechnology memory, biological memory, or otherdata storage media. Indeed, computer implemented instructions, datastructures, screen displays, and other data under aspects of theinvention may be distributed over the Internet or over other networks(including wireless networks), on a propagated signal on a propagationmedium (e.g., an electromagnetic wave(s), a sound wave, etc.) over aperiod of time, or they may be provided on any analog or digital network(packet switched, circuit switched, or other scheme). Those skilled inthe relevant art will recognize that portions of the invention reside ona server computer, while corresponding portions reside on a clientcomputer such as a mobile or portable device, and thus, while certainhardware platforms are described herein, aspects of the invention areequally applicable to nodes on a network.

FIG. 2 is a block diagram that illustrates the flow of data through thesystem 100, in one embodiment. Content is initially stored on a dataserver 210 that may be a user computer, data warehouse server, or otherinformation store accessible via a network. The data is accessed by abackup manager 220 to perform a regular backup of the data. The backupmanager 220 may be contained within the data server 210 or may be aseparate component as shown. For example, the backup manager 220 may bepart of a server dedicated to managing backup or other storageoperations. Backup data is stored in a backup data store 230 such as anetwork attached storage device, backup server, tape library, or datasilo. The content indexing system 240 accesses data from the backup datastore 230 to perform the functions described above. As illustrated inthe diagram, because the content indexing system 240 works with anoffline copy of the data, the original data server 210 is not negativelyimpacted by the operations of the content indexing system 240.

FIGS. 3-4 are representative flow diagrams that depict processes used insome embodiments. These flow diagrams do not show all functions orexchanges of data, but instead they provide an understanding of commandsand data exchanged under the system. Those skilled in the relevant artwill recognize that some functions or exchange of commands and data maybe repeated, varied, omitted, or supplemented, and other (lessimportant) aspects not shown may be readily implemented.

FIG. 3 is a flow diagram that illustrates the processing of the contentindexing component 120 of the system 100, in one embodiment. Thecomponent is invoked when new content is available or additional contentis ready to be added to the content index. In step 310, the componentselects an offline copy of the data to be indexed. For example, theoffline copy may be a backup of the data or a data snapshot. In step320, the component identifies content within the offline copy of thedata. For example, the component may identify data files such as wordprocessing documents, spreadsheets, and presentation slides within abackup data file. In step 330, the component updates an index of contentto make the content available for searching. The component may parse,process, and store the information. For example, the component may addinformation such as the location of the content, keywords found withinthe content, and other supplemental information about the content thatmay be helpful for locating the content during a search. After step 330,these steps conclude.

FIG. 4 is a flow diagram that illustrates the processing of the indexsearching component 130 of the system 100, in one embodiment. In step410, the component receives a search request specifying criteria forfinding matching target content. For example, the search request mayspecify one or more keywords that will be found in matching documents.The search request may also specify boolean operators, regularexpressions, and other common search specifications to identifyrelationships and precedence between terms within the search query. Instep 420, the component searches the content index to identify matchingcontent items that are added to a set of search results. For example,the component may identify documents containing specified keywords orother criteria and add these to a list of search results. In step 425,the component generates search results based on the content identifiedin the content index. In step 430, the component selects the firstsearch result. In decision step 440, if the search result indicates thatthe identified content is offline, then the component continues at step450, else the component continues at step 455. For example, the contentmay be offline because it is on a tape that has been sent to an offsitestorage location. In step 450, the component retrieves the archivedcontent. Additionally or alternatively, the component may provide anestimate of the time required to retrieve the archived content and addthis information to the selected search result. In decision step 455, ifthere are more search results, then the component loops to step 430 toget the next search results, else the component continues at step 460.In step 460, the component provides the search results in response tothe search query. For example, the user may receive the search resultsthrough a web page that lists the search results or the search resultsmay be provided to another component for additional processing throughan application programming interface (API). The component may alsoperform additional processing of the search results before presentingthe search results to the user. For example, the component may order thesearch results, rank them by retrieval time, and so forth. After step460, these steps conclude.

FIG. 5 illustrates some of the data structures used by the system. Whilethe term “field” and “record” are used herein, any type of datastructure can be employed. For example, relevant data can have precedingheaders, or other overhead data preceding (or following) the relevantdata. Alternatively, relevant data can avoid the use of any overheaddata, such as headers, and simply be recognized by a certain byte orseries of bytes within a serial data stream. Any number of datastructures and types can be employed herein.

FIG. 5 illustrates a data structure containing entries of the contentindex, in one embodiment. The offline content indexing system uses thisand similar data structures to provide more intelligent contentindexing. For example, the offline content indexing system may indexmultiple copies of data and data available from the multiple copiesusing a secondary copy of data stored on media with a higheravailability based on the location or other attributes indicated by thedata structure described below. As another example, the offline contentindexing system may prefer an unencrypted copy of the data to anencrypted copy to avoid wasting time unnecessarily decrypting the data.The table 500 contains a location column 510, a keywords column 520, auser tags column 530, an application column 540, and an available column550. The table 500 contains three sample entries. The first entry 560specifies a location to a file on the corporate intranet using a webuniversal resource locator (URL). The entry 560 contains keywords“finance,” “profit,” and “loss” that identify content within the file.The entry 560 contains tags added by a user that specify that thecontent comes from the accounting department and is confidential. Theentry 560 indicates that a spreadsheet program typically consumes thecontent, and that the entry is immediately available. Another entry 570specifies data stored on a local tape that is a personal email, and canbe available in about an hour. Another entry 580 specifies an offsitetape that is a presentation related to a cancelled project. The entry580 refers to offsite data that is available within one week due to thedelay of retrieving the archived data from the offsite location.

CONCLUSION

From the foregoing, it will be appreciated that specific embodiments ofthe offline content indexing system have been described herein forpurposes of illustration, but that various modifications may be madewithout deviating from the spirit and scope of the invention. Forexample, web pages are often unavailable and their content may changesuch that the offline content indexing system could be used to retrievepoint in time copies of the content useful for conducting historicalanalysis. As another example, although files have been described, othertypes of content such as user settings, application data, emails, andother data objects can all be indexed by the system. Accordingly, theinvention is not limited except as by the appended claims.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The word “coupled”, as generally usedherein, refers to two or more elements that may be either directlyconnected, or connected by way of one or more intermediate elements.Additionally, the words “herein,” “above,” “below,” and words of similarimport, when used in this application, shall refer to this applicationas a whole and not to any particular portions of this application. Wherethe context permits, words in the above Detailed Description using thesingular or plural number may also include the plural or singular numberrespectively. The word “or” in reference to a list of two or more items,that word covers all of the following interpretations of the word: anyof the items in the list, all of the items in the list, and anycombination of the items in the list.

The above detailed description of embodiments of the invention is notintended to be exhaustive or to limit the invention to the precise formdisclosed above. While specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whileprocesses or blocks are presented in a given order, alternativeembodiments may perform routines having steps, or employ systems havingblocks, in a different order, and some processes or blocks may bedeleted, moved, added, subdivided, combined, and/or modified. Each ofthese processes or blocks may be implemented in a variety of differentways. Also, while processes or blocks are at times shown as beingperformed in series, these processes or blocks may instead be performedin parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

These and other changes can be made to the invention in light of theabove Detailed Description. While the above description details certainembodiments of the invention and describes the best mode contemplated,no matter how detailed the above appears in text, the invention can bepracticed in many ways. Details of the system may vary considerably inimplementation details, while still being encompassed by the inventiondisclosed herein. As noted above, particular terminology used whendescribing certain features or aspects of the invention should not betaken to imply that the terminology is being redefined herein to berestricted to any specific characteristics, features, or aspects of theinvention with which that terminology is associated. In general, theterms used in the following claims should not be construed to limit theinvention to the specific embodiments disclosed in the specification,unless the above Detailed Description section explicitly defines suchterms. Accordingly, the actual scope of the invention encompasses notonly the disclosed embodiments, but also all equivalent ways ofpracticing or implementing the invention under the claims.

While certain aspects of the invention are presented below in certainclaim forms, the inventors contemplate the various aspects of theinvention in any number of claim forms. For example, while only oneaspect of the invention is recited as embodied in a computer-readablemedium, other aspects may likewise be embodied in a computer-readablemedium. Accordingly, the inventors reserve the right to add additionalclaims after filing the application to pursue such additional claimforms for other aspects of the invention.

1. A non-transitory computer-readable storage medium storinginstructions for controlling a computer system to identify archivedcontent, by a method comprising: creating a secondary copy of multiplecontent items, wherein the secondary copy is created based on a primarycopy of the multiple content items stored by one or more computersystems coupled via a computer network; storing a first subset of themultiple content items on one or more first storage media that areaccessible via the computer network; storing a second subset of themultiple content items on one or more second storage media that areaccessible via the computer network, wherein the second subset of themultiple content items is stored on the second storage media at a firsttime, and wherein, at a second time later than the first time, thesecond storage media become inaccessible via the computer network; forat least some of the multiple content items included in the secondarycopy: analyzing generally all of the contents of a content item; basedupon the analysis of generally all of the contents, generating one ormore entries for a content index, wherein the entries include text thatdescribes the content; and updating the content index to include thegenerated entries, wherein the generated entries include a location ofthe content item on either the first storage media, the second storagemedia, or both; receiving, at a third time later than the second time, asearch request, wherein the search request contains criteria for findingtarget content; searching entries within the content index using thecriteria for target content to create search results, wherein searchingentries within the content index comprises receiving an availabilitycriteria related to a content item; searching based on information aboutthe availability of the content item, wherein the availability is basedupon the location of the content item; and generating search resultsindicating the time required to access the content item based upon theavailability, wherein the search results include at least one searchresult identifying at least one content item that is stored on thesecond storage media inaccessible via the computer network; andproviding the search results in response to the search request, whereinthe at least one search result identifies the at least one content itemstored on the second storage media as being inaccessible via thecomputer network.
 2. The non-transitory computer-readable storage mediumof claim 1, wherein searching entries within the content index comprisessearching based on user-added attributes.
 3. The non-transitorycomputer-readable storage medium of claim 1, wherein searching entrieswithin the content index comprises receiving a range of time duringwhich a deleted content item was last available, searching based on atime the content item was deleted, and generating search results foraccessing the deleted content item.
 4. The non-transitorycomputer-readable storage medium of claim 1, wherein searching entrieswithin the content index comprises searching based on a time range. 5.The non-transitory computer-readable storage medium of claim 1, whereinsearching entries within the content index comprises searching areference copy of a content item.
 6. The non-transitorycomputer-readable storage medium of claim 1, further comprising afterreceiving the search request, creating the content index dynamicallybased on the content available in the system.